Manipulations of activity in one retina can profoundly affect binocular connections in the visual cortex. Retinal activity is relayed to the cortex by the dorsal lateral geniculate nucleus (dLGN). We compared the qualities and amount of activity in the dLGN following monocular eyelid closure and monocular retinal inactivation in awake mice. Our findings substantially alter the interpretation of previous studies and define the afferent activity patterns that trigger cortical plasticity.The quality of sensory experience during early postnatal life has a crucial role in the development of cortical circuitry and function. In the visual system, this role has been investigated by comparing the consequences of temporary monocular eyelid closure and pharmacological inactivation of one retina with those of normal visual experience (NVE). Previous studies have shown that eyelid closure and retinal inactivation have very different effects on visual cortex 1-4 . A brief period of lid closure causes long-term synaptic depression (LTD) of deprived-eye responsiveness, whereas a comparable period of retinal inactivation has no effect on deprived-eye responsiveness and instead causes an increase in the responses to stimulation of the nondeprived eye (see Supplementary Fig. 1 online). Understanding how lid closure and retinal inactivation differ from one another and from NVE is of great interest because it may reveal how deprivation triggers LTD and causes visual disability. We examined this in awake mice at the age of maximal sensitivity to visual deprivation.Bundles of electrodes were inserted in the dLGN (see Supplementary Fig. 2 and Supplementary Methods online) at the age of maximal sensitivity to monocular deprivation (∼postnatal day 28, P28) 5 . Baseline recordings were made with the contralateral eye viewing and the ipsilateral eye occluded. Activity approximating that during NVE was recorded in response to phasereversing sinusoidal gratings and natural scene stimuli. Unless otherwise indicated, results using grating stimuli are illustrated, as results from natural scenes did not differ qualitatively. Following the baseline recording session, we briefly anesthetized the mice and carried out eyelid closure, intraocular tetrodotoxin (TTX) injection or no manipulation (control). After >30 min of recovery from anesthesia, stimuli were presented for a second recording session.Although eyelid closure and retinal inactivation abolished the visually evoked responses, these manipulations had no effect on spontaneous activity, and therefore had no effect on recording

In an attempt to redesign science, technology, engineering, and mathematics (STEM) departments to be more inclusive of all student populations, institutions of higher learning are reviewing their programs, policies, and the ways they engage students. The Partnership for Undergraduate Life Sciences Education (PULSE) has been working with STEM departments over the past 10 years to improve the student experience by incorporating evidence-based teaching practices and creating curricula with a deeper focus on conceptual understanding of scientific principles, competencies, and the process of science.